Switch terminal head having insulative terminal separators



Jan. 22, 1957 E. N. JACOB! 2,7?8364 SWITCH TERMINAL HEAD HAVINGINSULATIVE TERMINAL SEPARATORS Filed Feb. 2]., 1955 Edward AIL/2750i!gww United States Patent SWITCH TERMINAL HEAD HAVING INSULATIVE TERMINALSEPARATORS EdwardN. Jacobi, Milwaukee, Wis., assignor to Briggs &Stratton Corporation, Milwaukee, Wis., a corporation of-DelawareApplication February 21, 1955, Serial No. 489,441

2 Claims. (Cl. 200-168) This invention relates to electric switches andrefers more particularly to a terminal head especially suitable for aswitch having a rotatable contactor, such as the automobileignition-start switch disclosed in the copendingapplication of Edward N.Jacobi, Serial No. 474,4l7, filed December 10, 1954.

In general it is an object of this invention to provide an inexpensiveterminal head for a switch having a rotatable contactor, which terminalhead may be readily stamped out of insulative sheet material and quicklyand cheaply assembled into a switch.

Another object of this invention is to provide a terminal headcomprising an insulative disk having terminals to which conductors maybe secured projecting from onev face thereof and with insulativepartition members between the. terminals to isolate the terminals fromone another and prevent inadvertent contact between conductors securedto them.

Still. another object of this invention is to provide insulativepartition members for thus isolating the terminals of arotatable switch,which partition members may be. fabricated as cheap and simple stampingsand are held in place. on a switch by cooperation with the terminal headand with those portions of the switch housing by which the terminal headis held in place on the housing.

With the above and other objects in view, which will appear as thedescription proceeds, this invention resides in the novel construction,combination and arrangement of. parts substantially as hereinafterdescribed and more particularly defined by the appended claims, it beingunderstood thats'uch changes in the precise embodiment of thehereindisclosed'invention may be madeas'come within the-scopeot'th'eclaiins.

The accompanying drawing illustrates one complete example of thephysical embodiment of the invention constructed according to the bestmode so far devised for the practical application of the principlesthereof, and in which:

Figure l is a fragmentary side elevational view of a switch having theterminal head of this invention installed thereon, portions being brokenaway;

Figure 2 is a disassembled perspective view of the terminal head of thisinvention;

Figure 3 is an end elevational view of the switch shown in Figure l, aportion of the switch housing being broken away; and

Figure 4 is a fragmentary sectional view taken on the plane of the line4-4 in Figure 3.

Referring now more particularly to the accompanying drawing, the numeral5 designates generally a switch, such as an automobile ignition-startswitch, only the rear portion of which is shown and which comprises ahousing having a substantially tubular or cylindrical wall 6. The rearwall of the switch housing i provided by a terminal head designatedgenerally by 7 and comprising a disk 8 of insulative material having anumber of fixed contacts 9 exposed at its front face and terminals 10projecting from its rear surface, with insulative partition 2,778,904Patented Jan. 22, 1957 members 11 interposed between the terminals toinsure against inadvertent contact betwen' conductors secured to theterminals.

The disk may be readily stamped or punched from any suitable insulativeplate or sheet material, such as plastic impregnated paper laminate. Itis secured in place across the rear of the switch housing by confinementof its edge portion between a forwardly facing circumferential shoulder12, provided by rolling in the rear edge portion of the cylindricalhousing wall, and a rearwardly facing circumferential shoulder 13 on theinner surface of the cylindrical housing wall which may be formedintegrally with the housing, as by the junction of a rearwardly openingcounterbore 14in which the disk is seated with the bore 15 in thehousing. A small spline lug 16 in the housing engages in a mating notch17 in the periphery of the disk to insure correct orientation of thedisk, and hence of the terminals thereon, with respect to the remainderof the switch mechanism.

Each of the terminals 10 projecting behind the disk comprises the rearportion of a stud having an enlarged head exposed at the front of thedisk to provide one of the fixed contacts 9, the rear terminal portionof the stud being preferably threaded to facilitate connection of aconductor thereto by means of a nut (not shown).

The several studs should be radially spaced from the center of the diskand circumferentially spaced from one another, but may be disposed onthe terminal head in any desired manner to cooperate with whateverrotatable contactor (not shown) is employed in the switch mechanism. Thelocations of the contacts and terminals on the terminal head aredetermined by the locations of holes 18 in the disk, in which the studshave a press fit. The contact arrangement shown in the drawingcorresponds to that of the contacts on the switch of the aforesaidcopending application, the herein disclosed terminal head being adaptedfor use with that switch, and the lug 9a on one of the stationarycontacts of the present terminal head is intended to cooperate with therotatable contactor in a manner described in said application.

The two partition members 11, whereby each of the terminals is isolatedfrom its neighbors to prevent'inadvertent contact between the conductorsconnected with the several terminals, are stamped from insulativematerial which may be similar to that fromwhich the disk is fabricatedbut is preferably of lesser thickness. In general the shape of thepartition members is not important and they may be semicircular,rectangular or substantially trapezoidal, as shown, but each should havea substantially straight longitudinal edge 21 which abuts the fiat rearsurface of the housing when the partition members are installed on theswitch with their surfaces substantially normal to the rear face of thedisk. One partition member has a medial slot 22 opening to thelongitudinal edge 21 thereof, and the other partition member has amedial slot 23 opening to its opposite longitudinal edge, the depth ofthe slot in each case being half the width of the partition member, andthese slots permit the partition members to be assembled with the medialportion of each partition member received in the slot in the other tohold the members together in cruciform relation, with their surfacessubstantially perpendicular to one another and their longitudinal edges21 coplanar.

The partition members, connected in this crosswise relationship, aresecured to the disk, each extending substantially diametrically acrossthe rear face thereof and with its surfaces perpendicular thereto, bymeans of a pair of integral tongues 24 on each partition member. Thetongues comprise endwise extensions of the partition member and projectlaterally beyond the longitudinal edge 21 to be snugly received inendwise aligned,

elongated slots 25 in the disk, opening to the periphery thereof. Thewidth of the tongue is substantially equal to the thickness of the sheetor plate material from which the disk is stamped, and the length of thepartition members is such that the outer edges of the tongues are evenwith the edge of the disk, hence the tongues are con- ,fined between thecircumferential shoulders 12 and 13 on the cylindrical'housing wall andthe partition memv bers are thereby held in place across the rear faceof the disk.

While the partition members preferably extend substantiallydiametrically'across the disk, they may be disposed a little to one sideof the center of the disk, as shown. In any event the elongated slots 25are substantially radial and equispaced circumferentially around thedisk, and are arranged in opposite pairswith the two terminal head maybe cheaply and inexpensively fabricated from a few simple parts stampedout of insulative sheet or plate material and has insulative partitionsbetween its terminals to preclude inadvertent contact between conductorsattached to the terminals.

What I claim as my invention is:

' 1. In a switch of the type having a housing with a tubular wallportion; means on said housing wall portion, near one end thereof,providing a pair of radially inwardly projecting axially opposedcircumferential shoulders; a flat disk of insulative material having itsperipheral portion tightly confined between said shoulders and therebysecured across said end of the housing, said disk having a pair ofopposite substantially radially elongated slots opening to itsperiphery; a pair of studs secured in said disk at opposite sides of aline joining said slots and spaced from the center of the disk, each ofsaid studs having a head exposed at the inner face of the disk toprovide a stationary switch contact in the housing and an elongated bodyportion projecting through the disk and beyond said end of the housingto provide I to the outer face of the disk, said tongues having portionsin said slots projecting substantially radially outwardly to theperiphery of the disk and tightly confined between said shoulders on thehousing wall, whereby the partition member is fixed to the housing in aposition interposed between said terminals to preclude inadvertentcontact between conductors secured to said terminals.

2. In an electrical instrumentality of the character described: atubular housing; means on one end of the housing providing a pair ofinwardly projecting axially spaced and opposing circumferentialshoulders; at flat insulative disk extending across said end of thehousing and having its peripheral portion clampingly confined betweensaid shoulders to secure the disk to the housing, said disk having twopairs of substantially diametrically opposite slots opening to itsperiphery, said slots being substantially equispaced circumferentially,and said disk having a plurality of circumferentially spaced holes, eachintermediate circumferentially adjacent slots, in which terminals aresecurable; a pair of flat insulative partition members disposed edgewiseon the outer face of said disk, each in line with one pair of slots, andeach having a medial slot opening to one longitudinal edge thereof inwhich a medial portion of the other partition memher is received, sothat the partition members are thereby held with their surfacessubstantially normal to one another and with a longitudinal edge on onepartition member substantially coplanar with the corresponding edge onthe other; and means for securing said partition members in place on theflat outer surface of the disk with the partition members substantiallynormal to said surface of the disk and extending betweencircumferentially adjacent terminal holes therein to precludeinadvertent contact between conductors secured to terminals in saidholes, said means comprising a tongue at each end of each of thepartition members projecting from said longitudinal edge thereof andsnugly engaged in one of said slots in the disk, said tongues havingretaining portions in said slots which are equal in width to thethickness of said disk and project outwardly to the periphery of thedisk, said retaining portions on the tongues being clampingly confinedbetween said shoulders on the housing.

References Cited in the file of this patent UNITED STATES PATENTS1,532,098 Anderson Mar. 31, 1925 2,526,255 Milbank Oct. 17, 19502,623,087 Latta Dec. 23, 1952 2,650,973 Jacobi Sept. 1, 1953

